The Use of Gypsum to Improve Soil Conditions

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Overview

This concerns all companies that have an interest in the use of gypsum for agricultural and ecological improvement. SEPA is planning to provide new guidance on the use of gypsum on land, but wishes to consult first to understand the impacts on business.

Why We Are Consulting

SEPA published an end of waste Policy Position for Gypsum from Waste Plasterboard in 2010[1]. If processed gypsum has been fully recovered in compliance with the SEPA Policy Position, the subsequent movement and use in plasterboard manufacturing, cement manufacturing, or as a soil conditioner is not be subject to the requirements of waste legislation. Recovered gypsum which does not meet the full terms of the SEPA position is still regarded as waste.

In 2012 it became apparent that high levels of hydrogen sulphide were emitted when recovered waste gypsum was used in animal bedding. In anaerobic conditions, such as where high amounts of easily decomposable organic matter (e.g. manures, slurries and sewage sludge) are present, the sulphate forms hydrogen sulphide gas which is both odorous and toxic. SEPA issued a clarification that waste gypsum poses a significant risk to both humans and animals and is not approved for use as a bedding material for livestock[2]. We understand this was a market that gypsum processors had previously relied on.

On the basis of advice from our soil science advisors SEPA is now considering adopting a further position which could impact on the use of recovered waste gypsum as a soil conditioner. A link to a copy of the draft position is included for your information. The purpose of the proposed guidance is to summarise the risks from using gypsum on land and outline the controls in place for the use of waste and non-waste gypsum. In essence the proposed guidance states that gypsum may be applied to land to provide nutrients to the soil at low levels but it should not be mixed with other organic material, such as manures, slurries or sewage sludge, due to the high risk of generating odour.

It is SEPA’s intention to introduce this guidance as soon as possible. However we are seeking your views on the potential impact of this on Scottish businesses.